Total syntheses of melodienones by redox isomerization of propargylic alcohols

A remarkable base-promoted methodology for rapid construction of the (E)- and (Z)-γ-oxo-α,β-alkenoic esters skeleton involved with readily accessed vinyl propargylic alcohols through modified redox isomerization was uncovered. This approach manifested its high simplicity and efficiency with excellent tolerance of functional substituents, which have led to the straightforward structural modifications for various natural products and efficient total syntheses of melodienone, homomelodienone, isomelodienone, and homoisomelodienone within 4 linear steps.